1. Field of the Invention
This invention relates to railway vehicle structure and in particular to a wear member for use between a pair of relatively moveable components of such structure.
2. Prior Art Statement
It is known in the art to provide a wear member comprised of a metal support supported by at least one of a pair of relatively moveable components of a railway vehicle for the purpose of protecting the components from wear.
For example, it has been proposed in U.S. patent application Ser. No. 27,340 filed Apr. 5, 1979 to provide a wear member comprising a metal support having a continuous planar supporting surface, a polymeric material, and means attaching the polymeric material to the support and supporting same against the continuous supporting surface for the purpose of providing a substantially structurally self supporting wear member. The wear member as disclosed in this patent application utilizes a reinforcing material in the form of a metal structure having openings therein and such metal structure is welded directly against the metal support whereupon a polymeric material is formed around the metal structure on one side of the metal support resulting in the polymeric material being reinforced only along its inside portion while defining an exposed outside portion which is basically unreinforced.
It has also been proposed, in U.S. patent application Ser. No. 841,175 filed Oct. 11, 1977, now U.S. Pat. No. 4,188,888, issued Feb. 19, 1980 to provide a so-called wear member or liner for center plate structure of a railway vehicle which has a reinforcing material, also in the form of an expanded metal structure, embedded substantially centrally between opposed walls or surfaces of a polymeric material which serves as a matrix for the metal structure.
However, the first-mentioned wear member is deficient because its outside unreinforced portion of polymeric material is the one subjected to wear and under normal pressure during use has the tendency to "cold flow". The second-mentioned wear member for center plate structure has apertured reinforcing metal structure centrally embedded in polymeric material thereof whereby the polymeric material has minimum tendency to cold flow, however, it is also deficient because it has minimum self supporting structural strength and basically must be used between confining bearing surfaces which it serves to lubricate.